Applications, including Web browsers, on mobile devices may display advertising. For example, a game application may display advertising while a user is playing the game. Such advertising includes, for example, “Download free web auction software. Click here for details”. Further, such advertisements may be targeted towards the user. For example, if the user enjoys gaming, an advertisement targeted to the user may include ad content such as “Try the new game Happy Birds”. To enable such ad targeting, some information about the user must be made available to the application, so that the application may provide the user information to an ads server which serves the ads. However, such user information may not be readily available to the application because of application sandboxing.
As recognized by the inventors, since each application on a mobile device runs inside a sandbox, the application cannot access any cookies of the browser or other applications to obtain the user's information for ad targeting. In one approach, the applications must request permission from the user to access resources. In another approach, the users must login and authenticate themselves to receive targeted ads. However, such approaches are intrusive, inconvenient, and time-consuming, and may cause the user to switch to some other activity. In light of such drawbacks, more convenient and secure approaches to identifying the user are desired.